Atomic Emission Rate Inside a Quantum Resonator

We present a general formalism for studying the emissionrate of an atom inside a high Q-factor quantum cylindrical resonator.The electromagnetic field structure inside such closed resonator is derived.Then the cavity modes are quantised, allowing the positiondependentatomic emission rate to be calculated. Depending on thecircumstances, the atomic emission rate may be increased or reduced,and in extreme cases is completely suppressed. Especially, in thequantum size system, the atomic emission rate is possible only via a few cavity modes. The calculations are carried out for the sodiumatoms immersed in an empty quantum size resonator.